This invention relates to liquid transfer devices used in laboratories, and more particularly, is directed toward a multi-channel pipetting device which enables the user to adjust the spacings between individual pipette tips.
Pipetting systems are used in laboratories for the transfer of relatively small quantities of liquids. The liquid is normally drawn into the tips by suction and is subsequently released into the wells of microtiter plates or other receptacles. Frequently the transfer involves patient samples which are moved to receptacles which are unevenly spaced apart. Because virtually all hand operated multi-channel pipettes have a fixed spacing between pipette tips, the transfer must be made by single channel pipettes, which is a slow and very inefficient process. Some large laboratories and pharmaceutical firms which perform thousands of transfers a day have purchased fully automatic robotic systems that cost tens or hundreds of thousands of dollars, but those systems are beyond the reach of small and medium size firms.
One important object of this invention is to provide a pipetting system which is relatively inexpensive but which is capable of being adjusted to vary the spacing between the pipette tips so that liquid may be transferred to receptacles to another set of different spacing.
A more specific object of the present invention is to provide a pipetting system that enables the user to individually adjust the pipette tips from one set of spacings to another.
It is a further object of the present invention to provide a pipetting system that easily and effectively secures the pipette tips in the selected position.
It is a further object of the present invention to provide a pipetting system that is of simple construction and therefore relatively inexpensive to manufacture.
It is a further object of this invention to provide an adjustable pipetting system that is easy to operate and does not require complicated adjustments for use.
It is a further object of the present invention to provide a hand-held pipetter having a tip removing assembly that removes tips safely and efficiently without regard to the particular orientation of the tips.
It is a further object of the present invention to provide a pipetting system having a tip removing assembly that requires a minimum force to remove the tips.
The system is embodied in a boot-shaped instrument having a housing with a handle section and a foot or lower section. A plurality of fittings aligned in a row extend downwardly from the foot. The fittings are separate from one another and are slidably mounted on a track alone the foot such that the various positions ar limited by the length of the track and the width of the mountings that carry the fittings. A clamping plate inside the housing releasably secures the fittings to the track in any selected position.
A tip removing mechanism operated by a trigger on the handle section has a stripper that can remove the disposable tips from the fittings regardless of the spacing of the fittings. As the trigger is squeezed, the stripper pushes the tips off the fittings. In order to reduce the overall force required to eject the tips, the ejecting surface of the stripper is stepped so that groups of tips are engaged in sequence causing first one group and then another to be pushed off the fittings.
The many objects and features of this invention will be better understood and appreciated from the following detailed description of the preferred embodiment thereof read in connection with the accompanying drawings.